1. Field of the Invention
This invention relates to switching means to be employed in combination with an apparatus to be employed in the process of disinfecting hydrophilic contact lenses. More particularly, this invention relates to a switch for actuating the disinfecting process which actuation cannot occur unless the cover of the apparatus is completely closed relative to the apparatus.
2. Description of the Prior Art
Hydrophilic contact lenses being water absorbant require daily care by the patient in order to destroy pathogenic microorganisms which accumulate on and can contaminate the lenses. Daily care, i.e. disinfection, is necessary, for the microorganisms are a potential source of eye infection if they are not destroyed.
A number of methods have been suggested for disinfecting hydrophilic lenses such as, for example, boiling the lenses immersed in a saline solution for at least 10 minutes at +100.degree.C, or chemically treating the lenses. Boiling, which requires the attention of the patient is a time consuming process and the high temperature treatment can, with the passage of time, have adverse affects upon the lens. Chemical treatment requires the utmost care since after treatment the chemicals must be properly and thoroughly flushed from the lens.
In order to destroy the pathogenic microorganisms, it is sufficient to disinfect the lens.
The physical requirements for disinfection are that the object be heated at a sufficient temperature and for a sufficient time so as to cause the destruction of pathogenic microorganisms on the lenses.
In U.S. Pat. No. 3,801,278 of Wagner et al. issued Apr. 2, 1974 an apparatus is disclosed for mass sterilization of hydrophilic lenses. The apparatus is particularly designed for the ophthalmologists and optometrists. The patent discloses and teaches that the lenses are to be sterilized. The device is not suitable for home use since it is bulky and designed around the needs of the professional who has to treat lenses in bulk. Because the lenses are sterilized the apparatus is not particularly desirable for constant use by a patient who is involved with treating only a pair of lenses. The device furthermore employs a mechanical timer for controlling its operation.
U.S. Pat. No. 3,720,402 of Cummins et al., issued May 13, 1973 describes a cleaning device for contact lenses. The device, as described, cannot effectively be employed for disinfecting since the temperature requirement for disinfecting is not obtained. The device additionally depends on a mechanical timing mechanism for its operation which, if it should not properly function, could result in the evaporation of the cleaning fluid and the concomitant adverse environment for the treated lenses.
U.S. Pat. No. 3,585,362 issued June 15, 1971 describes an apparatus which depends on the rapid conversion of a quantity of water to steam for sterilizing contact lenses. This device and others which similarly depend on the conversion of water to steam for the treatment of hydrophilic contact lenses must be carefully cared for by the patient in order to avoid the corrosion of metal parts as a result of deposits such as iron, calcium, chloride ions and the like which will form if the device is not properly cleaned after each use.
U.S. Pat. No. 3,852,032 of Urbach, issued Dec. 7, 1974, describes a method of sterilization of hydrophilic contact lenses by means of U.V. radiation. In order to avoid embrittlement and disintegration of the polymeric material constituting the contact lens, the lens material must contain ultraviolet stabilizers. The method and apparatus described is not universally applicable since few, if any, lenses comprise U.V. stabilizers.
In concurrently filed application entitled Apparatus & Process for Disinfection of Hydrophilic Contact Lenses there is described a simple device for disinfecting hydrophilic contact lenses which device is applicable for disinfecting hydrophilic lenses. The device does not depend on the production of steam for the transfer of heat from the apparatus to the lens, is easily carried about in a woman's purse or in a man's shirt pocket, and is free of mechanical timing mechanisms.
It is desirable that the apparatus include a method of activation of the disinfecting process such that said process cannot be initiated unless the apparatus is in a closed mode with relationship to its housing.